AIMS AND LEARNING OUTCOMES

The purpose of this course is to disseminate the basic principles and methods for modelling environmental processes, in order to solve simple problems related to the assessment of environmental contamination and health risk. Applications are about the diffusion and repartition of chemicals into soil and groundwater, evaporation of liquid spills, diffusion of chemicals from packaging to food, absorption and diffusion of pollutants into different materials, dermal contact.

Attendance and active participation in the proposed training activities (lectures, exercises, lab activities) and individual study will allow the student to:

- write mass and energy balances for reacting systems at macroscopic scale and apply them to environmental systems and processes;

- write constitutive equations for thermodynamic equilibrium and chemical kinetics and apply them to environmental systems and processes;

- define the control volume, the boundary conditions and write the equations of change for mass and heat transfer at local scale. Apply them to simple environmental systems and processes.

TEACHING METHODS

The course provides lectures (with the help of slides provided by the teacher) and exercises/ laboratory activity.

Theoretical contents alternate exercises and simulation activity aimed at encouraging the learning and discussion of specific problems involving the analysis of different approaches from macroscopic to local scale.

Transversal competences as autonomy of judgment will be acquired during the development of the proposed project, to be carried out in a group, communication skills will be acquired during the oral examination (presentation of the project and discussion about adopted methods and tools).

SYLLABUS/CONTENT

1. Introduction and definitions (5 hours)

• Main chemical-physical quantities and their units.
• Closed and open Environmental Systems (ES). Definition of the control volume and its boundaries.
• Physically based (mechanistic) models and phenomenological models.
• Scales of representation.
• Static and dynamic ES. Environmental Compartments (EC) and Environmental Interfaces (EI).

1. Constitutive equations (10 hours)

• Recalls on the first and second law of thermodynamics
• Chemical and phase equilibrium
• Chemical kinetics in homogeneous and heterogeneous ES.
• Chemical potential. G-L equilibrium. Raoult and Henry laws. L-L, L-S, G-S equilibrium.  Partition coefficients. Fugacity based models.

1. Mass and energy balances for reacting ES (12 hours)

• Macroscopic scale: Filling, discharging, mixing, heating of reacting ES.
• Local scale: diffusion, adsorption, desorption, evaporation in reacting ES.

1. Assessment of contamination and Environmental Risk (5 hours)

• Human Health Risk Assessment (HHRA) and Ecological Risk Assessment (ERA).
• The main four steps of Environmental Risk Assessment.
• Definitions of sources, receptors, pathways, exposition routes and effects.
• Definition of Reference Dose and Slope factor;
• Hazard Index (HI), Hazard Quotient (HQ), Cancer Risk (CR)

1. Case studies (18 hours - use of Matlab & Simulink)

• Mixing of reacting chemicals in gas /liquid phase (macroscopic scale: dynamic models)
• Liquid spill of H-C in seawater/soil (local scale: evaporation and diffusion; diffusion with reaction in homogeneous phase)
• Mass transfer of chemicals in packages, food, skin (local scale: diffusion in different layers with reaction at the boundaries or chemical equilibrium).

RECOMMENDED READING/BIBLIOGRAPHY

Course handouts and slides supplied by the teacher (full bibliography is also contained)

R. Byron Bird, Warren E. Stewart, Edwin N. Lightfoot, “Transport Phenomena”, John Wiley & Sons, 2006.

R.H. Perry, D.W. Green, “Perry’s Chemical Engineers’ handbook” VIII ed., Mc Graw Hill 2008.

M.C. Annesini, “Fenomeni di trasporto. Fondamenti e applicazioni”, Edizioni Hoepli.

Kalliat T. Valsaraj, “Elements of Environmental Engineering Thermodynamics and Kinetics”, Lewis Publishers, Washington 2000.

O. Paladino, G. Hodaifa, M. Neviani, M. Seyedsalehi, A. Malvis , “Modelling in Environmental Interfaces”, in Advanced Low-Cost Separation Techniques in Interface Science, Vol. 30 1st Edition, G. Kyzas and A. Mitropoulos Eds, Academic Press, 2019.